RELATIONSHIP BETWEEN TM LANDSAT-5 SPECTRA L RESPONSE AND COFFEE AGRONOMIC VARIABLES/

Perennial crops have complex spectral behavior. Factors such as row-sp acing, shadowing, crop seasonal characteristics, and substrate impinge noises that are difficult to interpret at satellite level. This study describes the influence of some coffee culture factors on spectral re flectance at TM/Landsat-5 level. At farm level, 145 coffee fields were selected. Agronomic variables like plant density and age, plant diame ter and height, vegetative vigour and volume of green leaves, row-spac ing and direction, substrate and soil spectral characteristics, and to pographic features were collected. A correlation analysis was performe d for agronomic variables only, and then the correlation between TM ba nds and agronomic variables was analysed. Some crop variables are well correlated such as coffee height and diameter, percent soil cover by coffee tree and harvest occurrence, pruning year and height. Pruning y ear and plant height were the most correlated parameters with TM1, TM2 , TM3, TM5, and TM7 bands. Those parameters seem to aggregate informat ion related to coffee phytomass and shadowing. A few agronomic variabl es correlated with TM4, except vegetative vigour. Parameters related t o crop characteristics are more correlated with TM bands than paramete rs related to substrate and terrain geometry.